Background: In Taiwan, services provided by patients’ peers in the mental health care system are still lacking. Therefore, this study aimed to develop a community setting model by a training program for severe mental illness (SMI) patients’ peers that also have SMI in Taiwan. Method: This training program comprised of 13-h lectures, 15-h practice classes, and an eight-week internship. In 2018 and 2019, the trainees provided one-to-one services to service users with SMI during the internship at a halfway house. The satisfaction and outcomes among all participants were measured in this training course. Results: The total mean satisfaction score in the training course for trainees (10 items, n = 13) and internship services for service users (12 items, n = 29) were 4.7 ± 0.4 and 4.6 ± 0.5, respectively. Among the trainees, 11 demonstrated improved Brief Psychiatric Rating Scale-18 (BPRS-18), Chinese Health Questionnaire-12 (CHQ-12), and Global Assessment of Functioning (GAF) scores after the whole training course. Among the 29 service users, their scores in the BPRS-18 and CHQ-12 decreased, whereas their scores in the GAF increased significantly under the internship service. Conclusion: In this pilot study, the trainees and service users who received internship services felt satisfied. The service providers and users with SMI both showed better clinical outcomes.